This invention relates to an improved light source for illuminating and examining devices such as laryngoscopes.
Laryngoscopes generally comprise a detachable blade and a cooperating handle which are connected together in an L-shaped configuration. The handle serves as an enclosure for one or more batteries which energize a light source in the top of the handle. The switch for energizing the light source is usually positioned at the top of the handle immediately adjacent to the light source and is activated by the blade when it is connected to the handle into an operative position. Light from the light source is directed to the light receiving face at the proximal end of the light conductor disposed in or on the blade. Light passes through the light conductor to the distal end thereof to illuminate the field of view such as a patient's mouth and larynx during the examination thereof by medical personnel. Although the instrument is useful in examining the larynx, the primary function of a laryngoscope is to expose the larynx in order to facilitate the insertion of an endoptracheal tube into the trachea of the lungs to administer anesthetic gases therein.
With the prior metallic laryngoscopes, the electrical connections and assembly of the light source, the switch and the battery pack involved extensive manual labor, but the labor costs were relatively insignificant in comparsion with the costs of the metal handle casing and the metal blade. However, with the advent of disposable plastic blades and plastic handles, the costs for manual assembly for the handle components became extremely high in comparison with other manufacturing and material costs.
The development of a metal coated plastic support frame described and claimed in copending application Ser. No. 669,473, filed Nov. 8, 1984, by the present inventor was a substantial advance in the art inasmuch as the battery holder, the switch and the light components could be produced with a single unit of metalized plastic which is formed by injection molding of a suitable plastic material such as acrylonitrile-butadiene-styrene polymers (ABS).
While the metallized plastic support frame described in the aforesaid patent application was a substantial advance, the manufacture and assembly of the light source still involved much manual labor and relatively high labor costs. The present invention, which provides a relatively cheap and simple to manufacture light source, was developed to satisfy the needs for simplifying the assembly and lowering the cost of the light source for illuminating and/or examining devices such as laryngoscopes.